Television system



Aug. 29, 1933. A. N. GOLDSMITH TELEVIS ION SYSTEM Filed Aug. 14, 1930INVENTOR ALFRED N GOLDSMITH Patented Aug. 29, 1933 r I V UNITED STATESPATENT oi-"riot if j 1,924,277 TELEVISIONVSYSTEM Alfred n. Goldsmith,New York, N. r; maggot w Radio Corporation of America; a Corp ration ofDelaware Application-August 14, 1930. 7 Serial No. 475,137 a 13 claims.(c1. 178+6) The present invention relates to television systems, and, inparticular, to television systems wherein the transmitter of the systemis soarranged that both approaching and receding shots may be made whilestill maintaining an automatic focusing of the transmitted picture imageupon the scanning element, or of a light spot, as I in spot ordirectscanning", upon the picture surface.

In all cases where it is necessary or desirable to transmit a completetelevision program, with or without a sound accompaniment, it isdesirable to provide a system whereby the transmission of the subjectmatter may not be interrupted or delayed by shifting from one picture toanother. By this I mean that, during the transmission of theprogram,'one picture'subject might be relatively close to thetransmittingele- 'ment while another picture subjectmight be somewhatremoved therefrom. This relationship will change, of course, many times,dependent upon the type of action transmitted. It may be- 7 desirablealso to transmit a picture subject while the subject is moving toward oraway from the transmitting element. In any "such cases as abovesuggested, it is necessary that the picture subject be maintained inproper focus in order that a clearly defined image mayibe viewed at thereceiving end of the system.

It is, therefore, one of the objects ofmy invention to provide a systemfor automatically maintaining properfocus during both approach.- ing andreceding shots or. during the change between near and distant images,and, at the same time, toprovide a system capable of accomplishing theseresults which will not require any adjustment whatever during operationexcept slight movements of the complete transmitting assembly inaccordance withthedistance at which the picture subject is locatedrelative to the transmitting element. e V i A- further object is toprovide a system for transmitting television subjects wherein the lensarranged to focus the picture subject upon the scanning element or alightspot on the subject is automatically adjusted in accordance withthe position of a carriage or like element carrying the completetelevision transmitter assemblage.

Other objects are to provide an arrangement for transmitting televisionpicture images which; at the receiver, will bear a true likeness to thetransmitted subject because of the fact that the transmitted subject iscontinually maintained in proper focus with respect to the scanningelement, and to provide a system for producing this er the carriagewithrespect to the subject.

to those skilled in the art to which the, invention relates by makingreference to the accompanying drawing forming apart of my disclosure,which illustrates two examples of a suit:

ablefassemblage for carrying out the aims and objects of this invention.

According to the drawing showing two of the many forms of theinvention,- it will be observed p that the television scanning isproduced by means -of a rotatable disk having a spiral track thereonprovided with either lenses or apertures, mirrors orother optical means,so arranged that suc- I cessive picture elements, as scanned, influencethe current output'from a suitable light translating element. Thecurrent output from the light translating element may then representdirectly a function 'of the intensity of light and shadow on eachelemental area of the transmitted'subject. In addition to the scanningfeatures which have previously been known in the art, I have provided asuitable lens system for focusing the picture image to be transmittedupon the scanning element, as in indirect scanning, or a light spot fromthe scanning element upon the subject, as in direct or spot scanning,and this lens element'hasbeen so arranged that it is automaticallyadjusted in accordance with.v the position of the transmitted picturesubject with respect to the scanning element; In accordance with apr'eferredembodiment of my invention,

I have so arranged the system that the complete transmitter assemblageis mounted upon, a'car-I riage which may be moved back and forthrelative to the picture subject tobe transmitted, and as V the carriageis moved, in accordance with the distance of the picture subject fromthe scanning element, the focusing lens for focusing theisub- 10 jectupon the scanning element or the light from the scanning element on thesubject is automatically adjusted without need of the operator doing anymore than to observe the position According to the accompanyingdrawing,Fig. 1" illustrates one form 0i system suitable for in-e direct scanningwherein .the image to be transmittedis suitablyfocused upon the scanningelement; and,-

N ;v a

110', I bear :u on xthei guide :rail ;35 which :isinturn Fig.2illustrates one form of apparatus capable of indirect or spot scanningwherein a light beam is suitably focusedv upon the picture image forlight corresponding to the intensity of light and shadow of eachelemental area of the picture subject 1 is caused topass throughthe-apertures or lenses '1'? carried by the disk and throughthe opening13 in the housing 11 ifor the photo .cll ,9, so that the photo cell 9 1ssubjected to all varying light intensities corresponding to each area ofthe picture. As the scanning'dis'k Wis rota-ted by means of the driveshaft 19 carried the bearing surface 21, the varying intensities oflight and shadow of the picture subject l affecting the ,photo--cell 9cause varying strength electric i-currents dzoiflowin the line 15.-l5.These -varying strength :electric "current impulses are 13113313151111:-

ably amplified by-any :desired type of amplifier and according to wellknown means, such :as have been idiSClOSGd for example by {NICOISODPatent No. 21 ;4f70;696, and mayv then, through appropriate modulatorsor .l'imitors be caused :to

influence a radio .oriwire'line transmission circuit.

lflhe scanning disk assemblage and the ,related photo cell amplifieriisrpreferably carried upon a ca'rriage 25 resting upon rollers -.orwheels 2-7] which is capable of moving :backzand forth upon the guide,129.. I i 7 As has :been above stated, a lens 3 :is [mounted directly inz-front-zof :the scanning XdiSk 7 :for'focusring the :picturerimage:upon the disk. :This lens its housing 5 is preferablyrsupported luponasmall carriage =3-lzhaying rollers Bit-adapted {to mounted non thecarriage element 25. Projected outwardly from the :standard '28, I :haveprovidedza :s'tud ;or projection element 357 @having .a :coil 'springi39mounted :ataone end thereof and:adapt- -ed.:to exert 'a forceagainst thecarriage element :Iitl iin thedirection shown by the iazrmw, 550M181;carriage celement :31 tends to 'IUVB'LiO the mtghtas:shownby the:drawing. @nethenpposite end of the carriage 3.141s zmounteil a :pin A1:car-

.rying' .a :roller '43 which is adapted tosbear upon depending .uponwhether the carriage 25 toward nrzatway from1the scanned picture subjectl. The beam :surface ".45 :is :so :sha-ped that the pitch of the camistrepresented by the distance l 47., and :substantially'according tothe well known law' f .T J 2-41 1 A ;F .f1

' where F equals "the focal .length of the lens 'fl is equal tothe'backiocus, and J2 equals the front-focus or the working-(distance,Thus, if the carriage is moved, the imaged the object ion the scanningdisk is at alltimes .maintained :in

- proper focus, since, by knowing the approximate distance of thesubject 1 from the disk '7, it is,

possible to move the carriage 25 toward or away from the subject inorder to properly focus the subject upon the disk, so that there will bea sharply defined image of the transmitted subject upon the disk whichmay influence the ,photolcellg9 in accordance with the varying intensityof flight and shadow of each elemental area of the subject.

'In'order to indicatethe position of lens 3, I

. have provided a pointer'57 on the carriage 31,

and this pointer will indicate, on scale 59, the

'lwor-king distance for which the system is adjusted.

New making ing showing a ;direct or spot scanning system, it

will be observed that an arrangement of subreference to Fig. 2 oi thedraw-:-

stantially' thes'ame type as the indirect scanning system of ,Fig. 1 hasbeen utilized with certain modifications r I I I According to Fig; 12,the :light {S ,forilluminating the subject 1' whichis @to be transmittedoriginates behindg'the scanning element 7 and "is ,projected through:the apertures or lenses, 1'"! thereof to-the lensrsystem 3. :As thelight passsee :es beyond the ;lens system 3, it converges so as toilluminateintensely anelemental area of the-sub- ;jectfor transmission,:iSuitable light responsive elements 9, so arranged as vto respond tothe' :di'fiusely reflected.lightfromxthe illuminated elef imentalareas-ofth'e subject ;1, may be placed at convenient points between thescanning element 7 and :the subject 1. As the scanning element .7rotates, :so as to cause light issuingfrornthe source S to passthrough-different lenses or apertures, itJis quiteapparentfthat'different elemental areas will be subjected to theintensepoint of light Iasyfocusedxupon the subject -1 by the lens system3. ,Thus, in a .linerfor line manner all elemental areas of the subject:are illuminated, :and :-in;propor.tion to the intensity of light andshadow .on all-of these elementaliareasa response occurs in the lightresponsive elements 9. In H cases where there area plurality 'of lightresponsive elements 19, it is,-0f course,e-desira'ble that 1.

53,11 'TOf these elements be parallelly connected.

- As was thecaserFig. lkit is possible that the subject for transmissionmayibe moving toward or away from thetelevision scanning device, and,

therefore, in order-to illuminate brilliantly each elemental area ofthesubject irrespective ofiits distance from the scanning device, I have:again provided-1a lens carrierfi for :the lens system 3 Whichimay :beadjusted as Ito :itsdistanceirom the scanning element through .amovement-of the carriage .25 which supports theiens system, the scanningelement, and the =light source. As was the-case inzconnectionwith Fig.1,'the lenssystem 3' :may :be adjusted by'movement 'of-the carriage 25-'which'.causes the cam-"45. to rotate; and .as it rotates the rollerr43which bears against'thejcam surface-45 :forcesthe lens carrier to theleft from the'position-shown againsttheforce of the spring 39, or itpermits the springjr39' to force the-lens carrier to the right fromtheiposition shown,

*While the invention has been shown and illustrated as applicable toscanning systems of the lens or aperture disk type, its hould be bornein mind that the ,principle herein disclosed is distinctly applicable toall'other types-of television systemasuch as thesystems using the Brauntube for scanning, such :as has been, disclosed by United-States patenttozwo kin $101,691,324; systems using a mirror disk: for scanning-as-;has been shown, for example,- byUnited statesappliappended claims.

, :1-,ee4=,a77

cation Serial No. 351,488, filed April 1 1929, by

Bernard Cioifari; oscillating mirrorftype of, scanners, such as has beenshown, forexample, by Edgerton Patent No. 1,605,930, and, infect, all.general types of television scanning, since the particular type ofscanning element per se forms no specific part of my invention, only inso far as it is necessary to coopera'te'with the lens focusing system toform a complete assemblage.

While the invention has herein been described.

in connection with television transmissiomit is believed that it will berecognized that the samev principle may be applied to facsimile systemswithout departing from the scope of the invention In such a case itwould be possible to have a photoelectric or otherlight sensitive devicedefinitely positioned relative, to the record carrying drum so that fordifferent size pictures different drums having a circumferential pathsubstantially equal in length'to the width or length .of the picturetransmitted (dependingof course, upon the manner of. positioning thepicture upon the record thereof, the full transmissiontime may beutilized for the message, whereasif a large drum were used for a smallpicture there would be a large part of the transmission time wasted. Insuch a case itis obviousthat where the size of drum is changed theadjustment of the optical system will appropriately form the image, asrepresented by suitable intensities of light and shadow of ele-.

mental picture areas, upon translating element.

Many other modifications and changes will, of course, suggest themselvesand at once become apparent to those skilled in the art to which theinvention relates, and I, therefore, believe myself to be entitled tomake any and all changes such the light sensitive as fall fairly withinthe spirit and scope of my present'invention as set forth bythehereinafter Having now described my invention, what I claim and desireto secure by Letters Patent is the following:

1. In combination, a scanning device for 'analyzing the varyingintensities of light and shadow upon cyclically recurring series ofsuccessive elemental areas of a subject of which the image is desired,an optical system associated with the scanning device, means forcarrying the said scanning device toward or away from the subject oftransmission, and automatic means operable upon movement of saidcarrying means for maintaining in focus the optical system used in the;

scanning operation. s

2.v In combination, a scanning device for analyzing the varyingintensities of-light and shadow upon cyclically recurring series ofelemental areas of a subject of which the image is desired,

an optical system associated with the scanning device, movable means forproducing relative movement between the subject of transmission and thescanning device, and automatic means operableupon movement of themovable means for maintaining in focus'the optical system used in thescanning operation. I

3. In combination, a scanning device for analyzing the varyingintensities of light and positions thereof relative shadow uponcyclically recurring series of successive elemental areas of a'subjectofwhich the image is desired,,an optical system associated with thescanning device for focusing a subject for transmissiongthereupon, meansfor carrying g both said scanning device and optical 'systemj-towardorjaway from the-subject forntransmission, and automatic means operableupon movement of said carrying means for maintaining the subject fortransmission in vice. 1- i I 4. In combination, a scanning device foranalyzing the varying intensities oflightand shad focus upon saidscanning de- .ow upon cyclically recurringuseries of successiveelemental areas of a subjectof which the image is L scanning device forfocusinga' subject fortrans mission thereupon, means forcarryingbothsaid scanning I device and optical ,system toward or I away from thesubject for transmission, and auto- ,desired, an opticalsystemassociated-with the vmatic means operable upon movement of said fcarrying means for focusing a spot of lightzupon an elemental area ofthe subjectfor transmission. I 5. In combination, a scanning element forany alyzing the varyingintensities of 'lightandshadow upon'cyclicallyrecurring series of successive elemental areas of a subject of which theimage is desired, an optical system associatedwith'the scanning elementfor focusing an image for transmission upon said scanning element, meansfor moving said scanning element toward. or away from the subject oftransmission, and means automatically operable upon movement of saidscanning eiement for maintaining 'the image of the subject oftransmissionin focus upon said scanning device for all positions thereofrelative to the subject of transmission. V

6. In a television system, a scanning element, alight source fordirecting light through said element and an optical system for directingthe light 'passingthrough said scanning element upon a subject fortransmission, means for moving said scanning element toward or away fromthe sub- 1 ject of transmission, and means operable upon movement ofsaid scanning device for focusing the light rays passing through saidscanning'element upon the subjectfor transmission for all scanningelement.

7. In a television system, a scanning element, a light sensitivemediumfor translating variable .intensitiesof light and shadow of asubject of to the position of the transmission as analyzed by saidscanning' elea ment into proportionatestrength electric currentimpulses, an optical system coordinatedwith said scanning element forfocusing an image of the subject of transmission thereupon, a ,movablecarriage carrying said scanning element and optical system and capable"of movement toward; or away from the subject of transmission, and meansoperable upon movement 0f said carriage relative to the subject oftransmission for simultaneously maintaining said optical system infocus.

8. In a-television system, a scanning element, a

1?!) source of light for illuminating a subject for] transmission, alight sensitive medium for trans- 1 lating variable intensities of lightand shadow of elemental areas of the subject for transmission intoproportionate strength electric currentimpulses, an optical systemcoordinated with said 1 scanning, element fo'rfocusing the light issuingfrom said source 'upon the subject for transmis 1 elementand opticalsystem and capable of movesion, a'movable carriage carrying saidscanning merit towardoraway irom the subject of trans- .0w uponcyclically wrecurrin g series of successive elemental areas of asubj'ectof which the image is desired, an optical system associated withthe scanning device, means for carrying said-scan- -ning.-.deviceitowardzor away from the subject of transmissioniwhich'isito be scanned,and auto- :matically operable means for simultaneously -ow 'iupon'cyclically :re'curring series of successive elemental areas of a(subject of which-the image :is :desired, an optical system associatedwith the scanning device, means for carrying said scanning Jdevic'etoward or away from the subject of transmission, "and .a cam surfacecooperating with :said optical system and adapted to be ashangechastoits positionby moticn'o'f the analyzting:sy'stem sojas to maintainautomatically said optical :system infccus during .moticn of saidscanning :d'evice relative to'the 'subje'ctof itrans-' mission.

511. In-combination,.ra iscanning device:for analyzing the varyingintensities :of light and shadow upon cyclically recurring series ofsuccessive "elemental areas of a 'subject'of 'Whl'Chthe image usana-7 isdesired, anaopticalsystem associated with the scanning -;device, meansfor carrying said scan ning' device toward or away from the subject oftransmission, and a rotatable cam surface cooperating with said opticalsystem and. adapted to be changed as to its-position by motionof the ranalyzing system'so as to maintain automatically 1 saidoptica'lsystemin-focus during motion of said scanning device relative to thesubject oftransmission. 12." In combination; a scanning element for analyzing thevarying intensities or lightand shad- 7 0w upon cyclically recurringseries of successive elemental areas of a subject of which the image eis 'desired'and an optical system associated with "the scanning elementfor focusing an image :of the subject for transmission upon said"scanning v elementya.movable carriage for carrying both *saidscanningelement and saidoptical system to-' ward or away from the subject oftransmission, and a cam surface in cooperative engagement with saidoptical systern and adapted to be-moved bythe motion of said carriagerelativ'e'torthe subject of transmission. for automatically adjustingsaid opticalsys'tem to maintain the i'ma'ge'oi subject in focus uponsaid scanning element.

13. Ina television system, a scanning'device'for analyzing varyingintensities of light and shadow on successive elemental areas of asubject of which an image is to be transmitted, an optical systemassociated with the scanning device, and

means for moving the opticalsystem to automati- I rally maintain it infocus uponirelative movement of thescanning device and the subjectscanned.

ALFRED NxGoLDsMITn;

said

DI S O L..A| M E R 1,924,277.-Alfred N. Goldsmith, New York, N. Y.TELEVISION SYSTEM. Patent dated August 29, 1933. Disclaimer filed June17 1937, by the patentee; the assignee, Radio Corporation of America,assenting. Hereby enters this disclaimer to claims 2 and 13 of thespecification.

[Ofiicial Gazette July 18, 1987]

